Image editing applications allow users to copy a region, a “source” region, from one image into another region, a “target” region, of an image. The target region may or may not be from the same image that the source region is copied from. However, simply copying a region into another region, even if part of the same image, may look unnatural. This is because the human visual system is more sensitive to contrast than intensity values.
FIGS. 1A-1D illustrate copying a source region into a target region using conventional copying techniques. Specifically, FIG. 1A is an image containing a colored cube. FIG. 1B illustrates an image containing a plate. FIG. 1C illustrates an image resulting from simply copying a source region from FIG. 1A into a target region in FIG. 1B. As illustrated in FIG. 1C, the boundary between the source region and the target region causes the source region to appear to be artificially placed into FIG. 1C.
Various methods, such as poisson blending, have been created to blend a source region into a target region, so that the source region appears to be naturally occurring in the target region. FIG. 1D illustrates an image resulting from copying a source region from FIG. 1A into a target region in FIG. 1B using poisson blending.
Poisson blending, like many image processing methods, may be computationally expensive. A user may not be able to quickly view results while making adjustments to the source region or the target region.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.